Insulator-pin.



C. J. DORFF. INSULATOR PIN.

APPLICATION FILED FEB. 3 1909.

Patented Oct. 19,1909.

UNITED STATES PATENT OFFICE.

conmin J. DORFF, or CHICAGO, ILLINOIS, ASSIGNOR T0 FREDRIC GREEK, oroHIcAeo,

, ILLINOIS.

INSULATOR-PIN.

Specification of Letters Patent.

Application filed February 3, 1909. Serial No. 475,758.

To all'whom it may concern:

Be it known that I, CONRAD J. DORFF, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Insulator-Pins, of whichthe following is a specification.

This invention relates to pins intended to support insulators such asthe glass insulators commonly used for telegraph and telephone wires.

The object of the invention is to improve the construction of suchdevices with a view to cheapness of manufacture and increasedefiiciency.

In the accompanying drawings, Figure 1 is a vertical central sectionthrough a device embodying the features of my invention. Figs. 2 and 3are horizontal sections on lines 2 2 and 3 3, respectively, of Fig. 1.Fig. 4 is a vertical central section, and Fig. 5 is a side elevation ofa modification.

The embodiment herein shown of my invention comprises a bracket or arm 1and a section attached to said arm upon which a glass insulator A may bescrewed. In this instance the arm 1 is formed from channel iron andcomprises the web 2 and the side flanges 3.

The screw section is of generally frustoconical form and is formed upfrom a piece of sheet metal. t It comprises the top portion 4 adapted tolie in a notch 5 formed in the upper end of the arm 1, being secured inplace by riveting over the upper projecting portions 6 of said arm. Thescrew section is rendered somewhat compressible by form ing therein aplurality of slots 7, in order to accommodate the often irregular screwthreads of an ordinary molded glass insulator, and also to provide forthe expansion and contraction of the pin under varying temperatureswithout liability of breaking the insulator, the screw section yieldingunder such conditions.

In the form shown in Figs. 1 and 3 inwardly extending'lugs Sand 9 areformed upon the lower end of the screw section at diametrically oppositepoints, the end of the lug 8 being reduced in width to form a tongue 10extending through an opening 11 in the web 2 of the arm 1, and toprovide shoulders 12 bearing against one side of said arm. The lug 9extends through said opening, its end being bent to retain it in placetherein. As shown in Fig. 3, the bottom of the screw section may contactthe sides of the arm 1 to assist in holding the screw section againstswinging with relation to said arm.

In the embodiment shown in Figs. 4 and 5 the lugs 8 and 9 are dispensedwith, the lower end of the screw section bearing against the sides ofthe arm 1 and preventing any considerable movement of said section withrelation to said arm.

Obviously changes in details of construction in the present embodimentmay be made within the scope of the invention, wherefore I do not limitmyself to the precise form shown and described.

I claim as my invention:

1. An insulator pin comprising a supporting arm, a hollow screw-threadedmember secured at one end to said arm,said member beingcircumferentially integral and having slots therein, and means at theother end of said member arranged to engage said'armto prevent relativemovement of said parts.

2. An insulator pin comprising a supporting arm, and a hollow,substantially frustoconical, screw-threaded member carried by said arm,the larger end of said member being reduced in diameter to contact thesides of said arm to prevent movement of said member laterally of saidarm.

3. An insulator pin comprising a supporting arm; a hollow screw-threadedmember carried by said arm, said member having slots therein terminatingshort of one end of said member, and two diametrically opposite lugs atone end of said member, said lugsextending into an opening in said arm,the end of one of said lugs being bent to retain it in place in saidopening.

4. An insulator pin comprising a supporting arm, a substantiallyfrusto-conical sheet metal. screw section having slots therein and anattaching. portion at one end secured to one of said lugs being bent toretain it in said arm, the other end of said screw sectlon place in saidopening. being reduced in diameter to contact the sides of said arm, andtwo diametrically op- CONRAD DORFF' poslte lugs on the last mentionedend of said WVitnesses: screw section, said lugs extending into an C.PAUL PARKER,

opening in said supporting arm, the end of GEORGE L. CHINDAI-IL.

